Fail-safe flashing of EPROM
US5701492A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1996 |
| Grant date | Dec 23, 1997 |
| Priority date | — |
| Expiry date | Mar 29, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1435
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A fail-safe flash for an EPROM that is arranged into separately erasable sectors proceeds in a stepwise procedure. The EPROM is divided into at least three regions including a boot block region, a file region and a directory region. The boot block region stores at least two independently erasable boot blocks, only one of which is designated as a current boot block, which performs scanning of the directory region so as to determine a current directory in the directory region. The file region stores all executables, including executables designated as critical and non-critical. The directory region stores multiple directories, only one of which is a current directory, which designates which is the current boot block, which of the files stored in the file region are available for loading for execution, as well as which of the files are critical and which are non-critical. In the first step to flash the EPROM, the unused region of the boot block is updated with the new boot block. In the second step of flashing the EPROM, critical files are flashed over non-critical files, and after correct installation of the newly-flashed critical files is confirmed, a new directory is written into t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.